progress on ex Z4

src/exercises/ex_z4/AuctionMain.java

@@ -1,23 +1,27 @@
 package exercises.ex_z4;
 
-import java.util.Random;
-import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.concurrent.Semaphore;
+import java.util.Arrays;
+
 
 public class AuctionMain {
     public static final String[] names = {
         "Sabrina", "José", "Patrick", "Salomé", "Lisa", "Alfred", "Annna", "Alex", "Kevin"
     };
 
+    public static final Item[] items = {
+        new Item("Album de Sabrina Carpenter"),
+        new Item("Chaussette gauche de Freddie Mercury"),
+        new Item("Peigne de Michael Jackson"),
+        new Item("Décapsuleur de Kurt Cobain")
+    };
+
     public static void main(String[] args) {
-        Semaphore mutex = new Semaphore(1);
-        ConcurrentLinkedQueue<Bid> bids = new ConcurrentLinkedQueue<>();
-        Auctioneer auctioneer = new Auctioneer("Paul", bids, mutex);
+        Auctioneer auctioneer = new Auctioneer("Paul", Arrays.asList(items));
 
         new Thread(auctioneer).start();
 
         for (int i = 0; i < names.length; i++) {
-            new Thread(new Bidder(names[i])).start();
+            new Thread(new Bidder(names[i], auctioneer)).start();
         }
     }
 }

src/exercises/ex_z4/AuctionState.java

@@ -0,0 +1,8 @@
+package exercises.ex_z4;
+
+public enum AuctionState {
+    PRESENTING_ITEM,
+    BIDDING,
+    SOLD,
+    FINISHED
+}

src/exercises/ex_z4/Auctioneer.java

@@ -1,23 +1,45 @@
 package exercises.ex_z4;
 
+import java.util.List;
+import java.util.Queue;
 import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.concurrent.Semaphore;
+
+
+import static exercises.ex_z4.AuctionState.*;
 
 public class Auctioneer implements Runnable {
     private String name;
-    private ConcurrentLinkedQueue<Bid> bids;
-    private Semaphore mutex;
+    private Queue<Bid> bids = new ConcurrentLinkedQueue<>();
     private Bid maximumBid;
     private Thread countdownThread = null;
+    private boolean isAuctionActive = false;
+    private AuctionState auctionState = PRESENTING_ITEM;
+    private final List<Item> items;
 
-    public Auctioneer(String name, ConcurrentLinkedQueue<Bid> bids, Semaphore mutex) {
+
+    public Auctioneer(String name, List<Item> items) {
         this.name = name;
-        this.bids = bids;
-        this.mutex = mutex;
+        this.items = items;
+    }
+
+    private void announce(String msg) {
+        System.out.println("[Auctioneer] " + msg);
+    }
+
+    public void presentItem() throws InterruptedException {
+        Item item = items.getFirst();
+        announce("Now selling this new item: '" + item.name() + "'");
+        announce("Get ready to bid...");
+        Thread.sleep(2000);
+        announce("Bidding open !");
+        auctionState = BIDDING;
     }
 
     public void placeBid(Bid bid) {
-        bids.add(bid);
+        if (auctionState == BIDDING) {
+            System.out.println(bid.bidder() + " bids $" + bid.amount());
+            bids.add(bid);
+        }
         notify();
     }
 
@@ -30,7 +52,7 @@ public class Auctioneer implements Runnable {
             Thread.sleep(1000);
             System.out.println("One");
             Thread.sleep(1000);
-            System.out.println("End of the Auction !");
+            auctionState = SOLD;
             notify();
         } catch (InterruptedException _) {}
     }
@@ -44,38 +66,52 @@ public class Auctioneer implements Runnable {
         return maximumBid;
     }
 
-    public void endAuction(){
-        System.out.println("End of the auction ! ");
-        notifyAll();
+    public AuctionState getAuctionState() {
+        return auctionState;
+    }
+
+    public void finalizeBidding() throws InterruptedException {
+        announce("And sold for $" + maximumBid.amount() + " !");
+        Item item = items.removeFirst();
+        announce(maximumBid.bidder() + " is now the proud owner of " + item);
+        maximumBid.bidder().addItem(item);
+        Thread.sleep(2000);
+        if (items.isEmpty()) {
+            auctionState = FINISHED;
+        } else {
+            auctionState = PRESENTING_ITEM;
+        }
     }
 
     @Override
     public void run() {
-        while (true) {
+        while (auctionState != FINISHED) {
             try {
-                mutex.acquire();
-                Bid current_bid = bids.poll();
-                if (current_bid == null) {
-                    startCountdown();
-                    wait();
-                    if (bids.isEmpty()) {
-                        endAuction();
+                switch (auctionState) {
+                    case PRESENTING_ITEM -> {
+                        presentItem();
                     }
-                    continue;
-                }
-                if (!bids.isEmpty()) {
-                    if (current_bid.amount() > maximumBid.amount()) {
-                        maximumBid = current_bid;
-                        System.out.println("New bid : " + maximumBid.amount() + " by " + maximumBid.bidder());
-                        mutex.release();
-                        return;
+                    case BIDDING -> {
+                        Bid current_bid = bids.poll();
+                        if (current_bid == null) {
+                            startCountdown();
+                            wait();
+                        } else {
+                            if (current_bid.amount() > maximumBid.amount()) {
+                                maximumBid = current_bid;
+                                announce("New best bid : " + maximumBid.amount() + " by " + maximumBid.bidder());
+                            }
+                        }
+                    }
+                    case SOLD -> {
+                        finalizeBidding();
                     }
-                } else {
-                    mutex.release();
                 }
+
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             }
         }
+        announce("The auction is now finished ! Thank you for participating !");
     }
 }

src/exercises/ex_z4/Bidder.java

@@ -1,30 +1,53 @@
 package exercises.ex_z4;
 
+import exercises.Utils;
+
 import java.util.Random;
 import java.util.ArrayList;
 import java.util.List;
 
+import static exercises.ex_z4.AuctionState.BIDDING;
+import static exercises.ex_z4.AuctionState.FINISHED;
+
 public class Bidder implements Runnable {
     private static int nextId = 0;
     private final String name;
     private final int id;
     private final List<Item> items = new ArrayList<>();
     private Double lastBid = null;
+    private final Auctioneer auctioneer;
 
-    public Bidder(String name) {
+    public Bidder(String name, Auctioneer auctioneer) {
         this.name = name;
         this.id = nextId++;
+        this.auctioneer = auctioneer;
     }
 
     @Override
     public void run() {
-        while(true){
-            Random rand = new Random();
-            double addon = rand.nextDouble(500);
-            lastBid += addon;
+        while (true) {
+            AuctionState state = auctioneer.getAuctionState();
+            if (state == BIDDING) {
+                Random rand = new Random();
+                double addon = rand.nextDouble(500);
+                double base = auctioneer.getMaximumBid().amount();
+                lastBid = base + addon;
+                auctioneer.placeBid(new Bid(this, lastBid));
+                try {
+                    Utils.randomSleep(100, 5000);
+                } catch (InterruptedException e) {
+                    throw new RuntimeException(e);
+                }
+            } else if (state == FINISHED) {
+                break;
+            }
         }
     }
 
+    public void addItem(Item item){
+        items.add(item);
+    }
+
     public String getName() {
         return name;
     }